In MasterImage 3D, Inc. v. RealD Inc., the Patent Trial and Appeal Board (PTAB) reaffirmed that the patent owner bears the burden of establishing the patentability of any amended claims proposed in an AIA trial over two categories of prior art: (a) the “prior art of record” and (b) “prior art known to the patent owner.” IPR2015-00040, Paper 42 (PTAB July 15, 2015). Nothing new there. What is new is the PTAB’s “clarification” of what constitutes such prior art: 

 “[P]rior art of record”… should be understood as referring to: a. any material art in the prosecution history of the patent; b. any material art of record in the current proceeding, including art asserted in grounds on which the Board did not institute review; and c. any material art of record in any other proceeding before the Office involving the patent.

* * *

“[P]rior art known to the patent owner”… should be understood as no more than the material prior art that Patent Owner makes of record in the current proceeding pursuant to its duty of candor and good faith to the Office under 37 C.F.R. § 42.11, in light of a Motion to Amend.

* * *

[W]hen considering its duty of candor and good faith under 37 C.F.R. § 42.11 in connection with a proposed amendment, Patent Owner should place initial emphasis on each added limitation. Information about the added limitation can still be material even if it does not include all of the rest of the claim limitations.

IPR2015-00040, Paper 42 (PTAB July 15, 2015)(emphasis added).

In the first two paragraphs above it appears that the PTAB was attempting to confine the sphere of prior art that the Patent Owner would be “required” to “discuss” in a motion to amend, in turn confining the art the PTAB would have to address. See, e.g., Reg Synthetic Fuels LLC v. Neste Oil Oyj, IPR2014-00192 (Paper 48)(“[D]uty of candor to the Office requires that [the Patent Owner seeking to amend] discuss any relevant prior art not of record but known to it. See 37 C.F.R. § 42.11; Idle Free, slip op. at 7.”)  In the third  paragraph above, however, the PTAB seems to unravel what it just confined by expanding the prior art sphere to a potential plethora of secondary art that might merely disclose the “added limitation.”

Given the PTAB’s emphasis on the duty of candor, it’s likely that Patent Owners will be reluctant to hold back any secondary art, even if believed cumulative. Thus, what initially appears to be the PTAB’s attempt at relaxing some of the burdens it has imposed on Patent Owners and an attempt to offer a procedure that better resembles the burden the statute places on the Petitioner to demonstrate unpatentability, on further review practically maintains a high burden on Patent Owners insofar it practically will have to “discuss” every bit of that secondary art, too, in its motion to amend.